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A231971
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Number of (n+1) X (2+1) 0..1 arrays with no element having a strict majority of its horizontal and vertical neighbors equal to one.
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1
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16, 56, 169, 550, 1764, 5680, 18225, 58596, 188356, 605458, 1946025, 6255180, 20106256, 64627982, 207734569, 667725402, 2146283584, 6898841796, 22175081569, 71277802674, 229109651716, 736431677100, 2367126871209, 7608702637640
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OFFSET
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1,1
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LINKS
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FORMULA
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Empirical: a(n) = 3*a(n-1) + 2*a(n-3) + 4*a(n-4) - 10*a(n-5) - 2*a(n-6) - a(n-8) + a(n-9).
Empirical g.f.: x*(16 + 8*x + x^2 + 11*x^3 - 62*x^4 - 14*x^5 + x^6 - 5*x^7 + 6*x^8) / ((1 - 3*x - x^2 + x^3)*(1 + x^2 - 3*x^4 - x^6)). - Colin Barker, Oct 01 2018
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EXAMPLE
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Some solutions for n=2:
..0..0..1....1..0..0....0..0..0....0..0..1....0..0..0....0..0..0....0..0..1
..1..0..0....0..0..1....1..0..1....0..0..0....0..0..0....0..1..0....1..0..0
..0..0..0....0..0..0....1..0..0....0..0..0....0..0..0....0..0..0....1..0..0
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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